Ductal Cancerization at the Pancreatic Neck Margin: Prevalence and Oncologic Relevance.

Abstract

Objective: To determine the prevalence of ductal cancerization at the pancreatic neck margin and to investigate its prognostic significance.

Summary background data: Ductal cancerization (cancerization of ducts; COD) describes the growth of invasive cancer in pre-existing ducts, and is frequently seen in pancreatic cancer resection specimens. Although COD is a well-defined histological diagnosis, it is not routinely reported on final pathology. Therefore, the prevalence and oncologic significance of COD at the pancreatic neck margin is unknown.

Methods: We queried our institutional database for pancreatic cancer resections performed between 2014-2018. Diagnostic slides were reviewed by expert pathologists for the presence of COD at the final neck margin, and statistical analysis was performed to correlate these findings with outcomes.

Results: Of 767 pancreatic resections meeting our eligibility criteria, final pancreatic neck margin was histologically evaluated in 309 cases (40.3%). COD was present at the final neck margin of 16 cases (5.2%). Overall-survival (OS) and recurrence-free survival (RFS) were both significantly shorter when COD was present at the final neck margin (HR 1.86; 95%CI 1.09-3.17; P=0.024 and HR 2.01; 95%CI 1.16-3.49; P=0.013, respectively) when adjusted for cancer stage, margin status, and adjuvant therapy in multivariate analysis. In contrast, presence of high-grade pancreatic intraepithelial neoplasia (HG-PanIN) at the final neck margin did not impact oncologic outcome.

Conclusions: Although COD is uncommon at the final pancreatic neck margin, it is associated with poor survival and increased recurrence. Therefore, and to clearly distinguish it from its mimicker HG-PanIN, routine reporting in histopathological assessment may be advised.